FOXL2 is a transcription factor belonging to the forkhead box （FOX） superfamily, characterized by the forkhead box/winged-helix DNA-binding domain. FOXL2 plays an important role in ovarian development and function.In postnatal ovaries FOXL2 regulates granulosa cell differentiation and supports the growth of the pre-ovulatory follicles during adult life. In addition, the FOXL2 protein will prevent the formation of testes by suppressing expression of SOX9. In mice, FOXL2 is also expressed in pituitary cells where it is required for FSH expression.